[SOLVED] Pass a System.Text.RegularExpressions.Regex as function parameter in Powershell 6

Pass a System.Text.RegularExpressions.Regex as function parameter in Powershell 6

Hello Powershell Experts,

I want to write a Powershell function that takes a System.Text.RegularExpressions.Regex as a parameter. My function header goes like this:

function Foo {
    Param([System.Text.RegularExpressions.Regex] $myRegex)
    # function body
}

And I tried to call Foo like this:

$MY_REGEX = new-object System.Text.RegularExpressions.Regex('<regex_body>')
Foo($MY_REGEX)

I got an error that says Cannot convert the "System.Object[]" value of type "System.Object[]" to type "System.Text.RegularExpressions.Regex".

I'm wondered why this is since I explicitly defined the regex with System.Text.RegularExpressions.Regex type. So I did .GetType() on my object and I got:

BaseType                   : System.Object
UnderlyingSystemType       : System.Text.RegularExpressions.Regex
FullName                   : System.Text.RegularExpressions.Regex

So now I'm confused why it's complaining about casting when the underlying type matches...

Can someone please point out what I'm doing wrong?

Solution

From the command line the below works for me with a bit of the relevant output provided. Can you provide an full example.

function foo { param ( [System.Text.RegularExpressions.Regex] $myRegex ) ; process { Write-Information -MessageData $myRegex -InformationAction Continue ; $myRegEx.GetType() | fl * } }
foo a.
$r = New-Object System.Text.RegularExpressions.RegEx("a.")
foo -MyRegex $r

and emits

a.

FullName                   : System.Text.RegularExpressions.Regex

Try using the last syntax shown.